There are known selective reflection members which use cholesteric liquid crystals as a member that can selectively reflect a desired wavelength in the wavelength range of visible rays to infrared rays. Since these selective reflection members are capable of selectively reflecting desired light (electromagnetic waves) only, the selective reflection members are expected to be used as, for example, heat ray reflective films or transmissive insulating films, which transmit visible rays and reflect only heat rays.
In regard to electromagnetic wave reflective films that reflect electromagnetic waves by using cholesteric liquid crystals, for example, the following documents are known. Patent Literature 1 discloses a laminated body comprising a transparent substrate provided with a thin film coating that reflects broadband near-infrared rays, and a filter made of cholesteric liquid crystals having a sharp wavelength selective reflectivity in the near-infrared part. This technology is intended to reflect near-infrared rays with high efficiency, without decreasing the transmittance of visible light. Furthermore, Patent Literature 2 discloses an insulating coating which includes one or more cholesteric layers that reflect at least 40% of incident radiation in the infrared wavelength range. This technology is intended to obtain a desired insulating effect by using cholesteric layers.
Furthermore, Patent Literature 3 discloses a polymer liquid crystal layer structure which comprises a polymer liquid crystal layer having light reflectiveness that has been enhanced by a particular method, and a supporting body supporting this polymer liquid crystal layer, the polymer liquid crystal layer structure having reflectiveness of 35% or higher to light having a particular wavelength. This technology is to be used mainly in liquid crystal displays (LCD), and the reflectiveness of the polymer liquid crystal layer is increased by using a fluorinated nonionic surfactant. Furthermore, Patent Literature 4 discloses a double-sided adhesive film for shielding near-infrared rays, which comprises a near-infrared ray-shielding layer having a selective reflection layer A formed from a polymer solidified substance layer having a cholesteric liquid crystal structure which transmits visible light but selectively reflects near-infrared rays in a particular wavelength range. This technology is mainly used in plasma display panels (PDP), and the influence of electromagnetic waves exerted by PDP to the surroundings is suppressed by the double-sided adhesive film for shielding near-infrared rays.